🔗Alaska Combination Vehicles — Question 3 of 10
You are driving a combination vehicle when the trailer breaks away, pulling apart both air lines. You expect the trailer brakes to come on and:
Answer: A
The tractor protection valve to close.
If all the air in the trailer is lost to a leak, the emergency brakes will be activated and the tractor protection valve will close.
Source: Alaska CDL Manual
All choices
- AThe tractor protection valve to close.
- BThe trailer supply valve to stay open.
- CThe tractor to lose air pressure.
Alaska CDL Combination Vehicles Test Info
Questions on Exam
20
Passing Score
80%
Time Limit
Typically 30 minutes; varies by testing location
Age Requirements
Intrastate: 18+ · Interstate: 21+
Alaska Division of Motor Vehicles
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More CDL Combination Vehicles Practice Questions
- Glad hands are usually connecting which of these?
- Why should you lock the tractor glad hands to each other (or dummy couplers) when you are not towing a trailer?
- After connecting the air lines but before backing under the trailer you should:
- The crack-the-whip effect is related to:
- Sudden turns or aggressive braking will have the greatest effect on which trailer?